Effect of elevated-temperature annealing on microstructure and properties of Cu-0.15Zr alloy

Cu-0.15Zr (wt.%) alloy with uniform and fine microstructure was fabricated by rapid solidification followed by hot forging. Evolution of microstructure, mechanical properties and electrical conductivity of the alloy during elevated-temperature annealing were investigated. The alloy exhibits good thermal stability, and its strength decreases slightly even after annealing at 700 degrees C for 2 h. The nano-sized Cu5Zr precipitates show significant pinning effect on dislocation moving, which is the main reason for the high strength of the alloy. Additionally, the large-size Cu5Zr precipitates play a major role in retarding grain growth by pinning the grain boundaries during annealing. After annealing at 700 degrees C for 2 h, the electrical conductivity of samples reaches the peak value of 88% (IACS), which is attributed to the decrease of vacancy defects, dislocations, grain boundaries and Zr solutes.

Automated summary

The Cu-0.15Zr alloy, fabricated by rapid solidification followed by hot forging, exhibits good thermal stability and high strength due to the significant pinning effect of nano-sized Cu5Zr precipitates on dislocation moving and the major role of large-size Cu5Zr precipitates in retarding grain growth by pinning the grain boundaries. After annealing, the electrical conductivity of samples also increases, attributed to the decrease of vacancy defects, dislocations, grain boundaries, and Zr solutes.